Sugarcane board product and process of making the same



United States Patent 3,464,881 SUGARCANE BOARD PRODUCT AND PROCESS OF MAKING THE SAME Robert B. Miller, 12540 126th Ave., Edmonton, Alberta,

Canada, and Taras W. Raczuk, Edmonton, Alberta, Canada; said Raczuk assignor to said Miller No Drawing. Filed July 1, 1965, Ser. No. 468,984 Int. Cl. B32b 5/12 US. Cl. 161-60 6 Claims ABSTRACT OF THE DISCLOSURE A structural building product manufactured from substantially uncrushed and pith-free sugarcane rind fiber bundles, said product formed by applying heat and pressure to the fiber bundles to bond and shape the bundles.

General background, objects and summary of invention This invention relates to the manufacturing of products from the stalk of sugarcane. More particularly, the invention relates to a novel process for treating sugarcane stalk to manufacture products from the outer rind of the stalk. The invention concerns improvements and the utilization of new discoveries with reference to United States application Ser. No. 384,462, filed July 22, 1964.

Sugar from sugarcane is produced by a conventional process which initially requires the violent destruction of the whole cane stalk by the use of massive machinery that cuts, crushes, shreds and breaks the whole cane stalk, and then, under enormous pressure, forcefully squeezes out the natural juices. This is referred to as milling; and while it has been used successfully in the extraction of the juices from the whole cane, it destroys many desirable structural characteristics of the rind portion of the stalk.

The primary commodity sought from the usual methods of processing sugarcane, and in fact the only commodity normally derived from sugarcane, is the actual sugar itself with little or no regard to the recovery of other products. A by-product of conventional sugarcane processing is bagasse, which is the fibrous or woody portion of sugarcane. A majority quantity of the bagasse produced at most sugarcane mills throughout the world is used as fuel for generating steam power for running the mills or it is burned merely to get rid of it. Since considerably more bagasse is produced than can be used as fuel, disposal of the excess is a serious problem. Large sums have been spent on trying to find ways of readily disposing of the bagasse or developing it into a commercial product. Efforts in this direction have not been completely satisfac- 1 has been discovered that the fibrous structure of the rind of sugarcane has special desirable physical and structural characteristics when the fibers are used in the form of fiber bundles. In the milling required by conventional processes for handling sugarcane, these desirable fiber characteristics are totally destroyed, and it is not possible under any circumstances in conventional sugarcane processes to preserve these characteristics. The problem concerns more than processing the rind alone, since it is necessary at the same time to consider the recovering of the juice from the stalk as well as the recovering of the rind fibers in such a condition as to preserve these characteristics. With conventional processes and apparatus it is virtually impossible to extract the juice from the sugarcane and at the same time maintain the rind fibers in a substantially discrete, continuous or undisturbed rind form so that the rind fibers can be utilized in the manner contemplated by this invention.

The rind portion of sugarcane stalk contains numerous fiber bundles, sometimes called fibrovascular bundles,

which are groups of elemental fibers in discrete elongated units. The elemental fibers of sugarcane rind resemble somewhat the elemental fibers of ratan and hackberry, but differ materially from the bast fibers as found in certain dicotyledonous plants as flax, hemp, ramie and jute. The fiber bundles in the rind of the sugarcane differ materially from the fibrovascular bundles of certain monocotyledons as sisal, hemp, rafiia, pineapple and ristra, manila hemp and other such plants. Although there are similarities between the elemental fibers of these plants and elemental sugarcane fibers, sugarcane rind contains fiber bundles which have been found to make the sugarcane rind particularly useful in the manufacture of products as will be explained.

The rind of sugarcane with which this invention is concerned is a highly useful product not heretofore obtainable by conventional processes and apparatus for handling sugarcane. The fiber bundles can be manipulated andprocessed into a variety of different forms; for example, building boards, planks, mats, flexible sheets, and the like, having a variety of uses. The rind product of this invention has fiber bundles which, in effect, are unbroken and undisturbed. When the rind strips are laid side-'by-side and subjected to suitable pressure, an action takes place termed fiber flow which will be explained in detail. While normally the fiber bundles make up discrete strips, when subjected to heat and pressure, the fiber bundles flow or move transversely with respect to their length and can be pressed into a continuous homogeneous mass of aligned long fiber bundles wherein each strip loses its identity as such.

The primary object of this invention is to provide a new method of handling and manipulating the rind portion of sugarcane and to produce therefrom a variety of products not heretofore obtainable.

Detailed description The sugarcane is harvested according to usual practices wherein it is customary that the leaves be removed before processing of the cane begins. Preferably, the field dirt is washed off the cane. Instead of handling the sugarcane stalks in mass or in bulk as in conventional processes, the sugarcane stalks are processed individually, although several stalks may be processed simultaneously. This is a radical departure from previous approaches in the processing of sugarcane.

The cuticle Wax is removed from the outer surface of each Whole stalk together with dirt and other foreign matter. Next, the epidermis is removed. Each whole stalk is then split longitudinally. The two stalk halves are separated, thereby exposing the pith which then is separate from the rind. The handling of the whole stalk and the stalk halves is done without any etfective squeezing of the pith to express therefrom the juice or without materially damaging or disturbing the long fiber bundles of the rind.

The rind strips then may be treated, collected, baled and stored, and eventually used in the manufacture of paper, chemicals, rayon, insulating board, or a variety of other products. The rind strips can be used to make rigid and semi-rigid building products and flexible mat products by subjecting a series of the rind strips to pressure and a binder under controlled conditions as will be explained in detail. The rind also may be used to provide laminates or finishes of various texture to numerous core or base materials by pressing the strips onto such materials. Furthermore, the rind'may be processed into special form especially suitable for storage or shipping.

Sugarcane is a member of the grass family grown in many tropical and subtropical areas of the world. In the past, it has been raised primarily and almost exclusively for the production of sugar. The principal part of sugarcane is the stalk which is made up of a number of joints called nodes and the stalk portion between the nodes, referred to as internodes. The leaf of the sugarcane plant consists of the sheath and the blade. The sheath is so situated on the node that it completely encircles the cane stalk. Each leaf usually extends the full length of the internode. The blades vary in width from one to three inches at the point of attachment to the sheath but taper to a sharp point. Leaf blades usually are four to five feet long and when growing on the plant, extend from the top portion. As the plant grows, the leaves along the internodes dry up and fall off.

The outer region or rind of the internode is hard and contains numerous fibrovascular bundles that strengthen the stalk. The interior of the stalk is mainly soft pith that contains most of the sweet natural sugar juice. The exterior of the mature internode is usually covered with a thin film of Waxy bloom or cuticle wax, as it is frequently called. Wax is also found throughout the rind portion as well as on the surface. A ring beneath the node contains a high concentration of wax. Expansion of the diameter of the stalk may result in growth cracks which may extend inwardly through the rind. Smaller, barely distinct, corky cracks may develop along the rind. Smaller, barely distinct, corky cracks may develop .along the internode and separate the fibrous materials of th rind for short distances.

Cleaning of the rind to produce fiber bundles free of foreign matter, loose fibers and other parts of the stalk is begun by removing the cuticle wax from the exterior of each separate stalk. This wax naturally adheresto the rind and is removed as a wax or powder. No attempt is made to remove that wax which extends through the rind, but only the cuticle wax adhering to the exterior of the rind portion of the stalk along the internodes and at the wax band. Since cane wax has cofmerical value, it may be collected and refined into commerically usable wax products.

The thin epidermis layer of fine, loose fibers is removed from the exterior of the rind in order to expose the relatively hard, strong fiber bundles. The epidermis has no structural value, and if left could materially lessen some of the physical as well as chemical properties of the rind strips ultimately produced. Since the epidermis of some varieties of sugarcane is quite colorful, for special uses, as will be explained, the epidermis may be left on. The important thing is to remove from the outside of the whole cane stalk all of the trash, wax, and loose matter, including the epidermis, although in some cases as just stated, the epidermis only may be left on. This cleaning of the stalk is effected without penetrating or damaging the fiber bundles of the rind.

The whole stalk with the exterior wax and epidermis removed is further processed by cutting it longitudinally throughout its length into two parts to expose the interior pith and by spreading the rind. The cutting and spreading serves the purpose of ultimately preserving the rind of the stalk in as large pieces as conveniently possible and at the same time opening up the stalk for access and removal of the juice laden pith. While this process has been carried out successfully by severing the stalk into two parts, it is possible to split each stalk longitudinally into more than two parts or to make a single longitudinal cut into one side of the rind only.

After the pith is exposed by splitting the stalk longitudinally, the pith is carefully removed from the stalk strips without squeezing the pith to express the juice therefrom. The stalk is then separated into two major components; namely, the soft pith containing most of the juice still held in the pith cells and the cleaned fibrous rind portions. At no point is the stalk subjected to pressure so as to express a substantial amount of juice; and, furthermore, the rind has not been subject to milling or any substantial physical force other than the single cutting action. The pith may be processed to remove the juice. The rind is in the form of strips the length of the 4 stalk pieces. Extremely crooked pieces of stalk can be cut crosswise into shorter pieces for easy handling prior to the start of process, if necessary.

Next, the rind strips are conditioned for utilization of the elongate, individual fibers. For making veneer and board products, for example, wherein it is desirable to position individual rind fibers into compact and continu ous special shapes, it is beneficial to loosen or break mechanically the natural bond between separate fibers without significantly lessening the longitudinal tensile strength of the fibers. This may be accomplished in a number of ways, for example, by passing the rind strips through a pair of rollers which serve to press and flatten the strips and spread apart the individual fibers due to the compression action of the rollers. Another way to accomplish this is to pull the rind strips longitudinally over and firmly against a substantial part of a curved surface, preferably with the exterior of the rind engaging the surface, so that the strips leave the surface at an angle with respect to the direction that the strips engaged the surface. This forces the strips from their normal curved shape to a flat shape. A rotatable wheel or roller may be used instead of a fixed curved surface; and for good results, the rind should engage degrees of the circumference of the wheel, leaving the wheel in the direction opposite to the direction of engagement with the wheel.

In a continuous sugarcane stalk handling operation, the rind will contain a considerable amount of moisture after the pith is removed. The conditioning of the rind to loosen the fibers should occur soon after the pith is removed and before the rind is dry; otherwise, if the rind is allowed to dry to ambient moisture or is dried artificially, it will curl and twist into distorted shapes and become extremely difficult to handle, particularly for purposes of placing the several fibers into presses or molds.

The rind strips may be washed by spraying or by dipping prior to conditioning the strips to loosen the fibers. It has been found that the strips dry readily in air, but if the strips are to be baled, it may be desirable first to pass the strips through a mechanical dryer. The rind strips thus obtained are relatively clean, undisturbed elongated groups of long fiber bundles. They may be handled and processed further in the particular manner to be described.

A desirable action or phenomenon may be obtained between the long fiber bundles of the rind making the strips highly suitable for the manufacture of a variety of articles. Movement of the individual fiber bundles laterally can be induced, which for the sake of convenience, hereinafter is called fiber flow. This has advantages considering both structure and appearance. When fiber fiow is induced, there is a tendency for the fiber bundles to separate and to move laterally of the longitudinal axis of the rind strip.

It has been discovered that the fiber flow phenomenon is due to or affected by a relationship of heat, pressure, time and moisture content of the rind. If the rind strips are subjected to sufficient heat; and if sufiicient pressure is applied for a sufficient time; and if the moisture content of the rind is sufiiciently high, fiber flow will occur. The fiber bundles apparently are held together by lignin and perhaps other naturally occurring binder substances. It appears that the natural binder substances are melted or that a chemical reaction occurs under conditions of heat, pressure, time and moisture, and when so affected, the adhesive properties of the binder substances decrease sufficiently to allow the fiber bundles to be moved relatively easily with respect to one another without disturbing or lessening the tensile strength or other physical characteristics of the individual fiber bundles. After the fiber flow conditions are relieved, that is after the temperature is dropped and the pressure is lessened, the adhesive properties of the natural binder substances return to hold the fiber bundles together in their new relative positions.

When several rind strips are laid side-by-side and overlapped, then subjected to fiber flow conditions, the fiber bundles are forced to interlock and to intermingle thereby combining the strips into a uniform, homogeneous mass of fiber bundles aligned generally in the same direction. The fiber flow, in addition to combining adjacent strips into a homogeneous mass, closes up the growth cracks and corky cracks so that they are no longer readily visible and, in some cases, actually nonexistent and the different shapes of the original internodes or the crooked configuration of the stalk tend to disappear.

Various items, such as boards, panels, veneer, planks, and the like, can be made out of rind strips utilizing the fiber flow phenomenon. The ranges of temperature, pressure, time periods and moisture content of the rind, in varying relative proportions are significant. Heat in conjunction with a high moisture content of the rind causes a release of a syrupy, brown liquid which may migrate through the rind fibers from high to low density areas and collect. An excessive release of this brown material may discolor the fibers. Upon cooling, the brown material appears to harden or set and its presence has an effect on the resultant desirable adhesive characteristics between the reoriented fiber bundles. The amount of brown material released appears to be proportional to the amount of moisture in the rind, and washing and squeezing of the rind prior to heating lessens the amount of brown material released. In order to control fiber flow and to enhance the desirable characteristics of items made from rind fiber,

the release of the brown material must be controlled. When pressure is applied to layers of rind as by a press, an extremely smooth surface on the resulting item can be obtained should sufiicient fiber flow be induced and controlled.

Different adhesive or binder materials, either low temperature setting or high temperature setting, may be added to the rind to hold the fibers together upon the application of heat and pressure. It has been found that especially desirable results can be obtained by using a high temperature setting melamine adhesive. Since melamine produces formaldehyde, it appears that the formaldehyde reacts with or causes a reaction of certain substances materially present in the rind such that extremely strong bonds between the fiber bundles are obtained Which are not obtained by use of other adhesives or resins.

By way of example, a variety of board and panel-like articles have been made under the following conditions and ranges: 300-600 p.s.i., applied by a press or mold to layers of rind strips; temperatures between 280 F. to 320 F.; moisture contents of the rind between to 35%, by weight; and pressing times between 3 minutes to 2% hours. Numerous observations have been made. For example, increasing pressures increase the density of the article and improve the fiber flow phenomenon. Increasing temperature above 280 F. has a direct effect on increasing the release and flow of the brown material. A moisture content of the rind of at least about appears to be necessary at about 600 p.s.i. and temperature at about 280 F. in order to obtain fiber flow, but an increase of moisture requires less pressure. Satisfactory articles have been made with rind having considerably less than 10% moisture content but with little fiber flow. A moisture content of the rind in excess of 25% causes water to be expressed on the application of pressure and heat which tends to wash away any added adhesive or resin material and to otherwise reduce control over fiber flow. The fiber flow phenomenon is not instantaneous but occurs over a period of time; and under fixed conditions of heat and pressure, a corresponding degree of fiber flow will result.

An important technique in utilizing the fiber of sugarcane rind to make articles by subjecting the rind to fiber flow conditions when a press or mold is used, is to cool the press or mold while pressure is maintained on the rind fibers. The press should be cooled to near or below 212 F.

before the pressure is released and the article is removed therefrom. The application of heat to the moist rind, in effect, creates steam and other gases which are confined within the. rind by the mold or by the platens of the press. This internal pressure must be released before the articles are released. If the press is not cooled before the pressure is relieved, the article tends to warp or swell when removed from the press or mold, the bond between fibers is adversely effected, and dimensions of the article are likely to change.

In general, highly satisfactory board and panel articles, and a variety of different shaped articles, can be manufactured from the rind of sugarcane using the following conditions: (1) a press or mold pressure of about 300 p.s.i., (2) a temperature of about 280 F., (3) time of heating of about 9 minutes for an article about inch thick or less, (4) a moisture content of the rind of about 15%, (5) cooling of the press or mold below about 212 F. before releasing the pressure. When these conditions are applied to rind strips, the fibers can be manipulated into a variety of shapes having a remarkably smooth surface.The articles thus formed exceed hardwoods in strength.

Boards, panels, veneer and like articles, can be made out of the long fiber bundles of sugarcane rind strips in the following manner. A number of strips are placed sideby-side on the lower plate of a press. The desired thickness of the resulting article can be selected by the depth to which the strips are piled in the press. When making the board or veneer, the nodes of the stalk can be aligned alternately so that adjacent strips do not have nodes located side-by-side. While there is no noticeable decrease in strength of the strips at the nodes since a number of fiber bundles on the inside of the rind continue through the nodes, the overlapping of the nodes adds considerably to the appearance of the resulting boards or mats, particularly if the exterior of the stalk is to become the exterior of the board or the veneer.

Preferably some adhesive or binder substance is added to bond the strips, although there is considerable natural bonding of the fibers due to naturally occurring substances in the rind and due to a mechanical interlocking of the fibers. The binder can be applied to each strip before it is placed in the press or it can be applied to the strips as necessary for consistency after the strips have been positioned in the press. The binder can be in wet or dry form and can be applied to the strips by dipping, spraying, dusting, painting, etc. Pressure and heat is then applied to the group of strips as explained previously. The dimensions of the resulting board or veneer depend on the size of the press and arrangement of the strips. A board structure can be formed by aligning all of the strips in one direction, by aligning strips crosswise in alternate layers, or by placing the strips in random fashion. Several thin veneer sections can be bonded together in a separate pressing operation with the fibers of adjacent veneers aligned at a right angle, similar to plywood. Boards with an endless variety of surface textures and patterns can be created. Different designs can be made by varying the alignment of the strips. The strips can be cut into different shapes to produce different designs or textures.

Rind strips can be made with the epidermis left on, and since the epidermis of certain varieties of sugarcane have considerable color this can be used to advantage. Boards having colorful surfaces can be manufactured by using rind strips with the epidermis left on as the exterior surface of the resulting board product. By using whole strips with long undisturbed fiber bundles as the interior of the board, the strength of the board can be maintained even though the fibers on the surface add little or no strength to the board.

The strips can be made up in rolls of continuous fiber bundles aligned adjacent one another in uninterrupted fashion throughout the length of each roll. The fibers may extend lengthwise or transversely when the strips are manufactured into the rolls, and the rolls can be made into practically any length or width desired. The long fiber bundles in the form of the rolls can be manufactured further into boards of considerable strength by aligning the bundles of several different rolls alternately in opposite directions, and then bonding the overlapping portions of the several rolls in a composite board structure having the bundles of alternate laminates extending in opposite directions. The number of such laminates employed may vary depending on the desired thickness of the finished board and the thickness of roll material used.

The rind strips, because of their unique and distinctive appearance, can be used effectively as an exterior laminate over plywood or other base or core material. This is done by taking an ordinary sheet of plywood, laying strips of rind thereon and applying heat and pressure after coating the strips with a binder material. This adds an extremely unique and ornamental surface to ordinary plywood. It has been found that plywood can be strengthened if the plywood is used as a base and a veneer of fiber bundles is applied thereto.

In the manufacture of boards and the like, it is necessary only to place the rind strips loosely in position in a press or mold and no special care or careful alignment of the strips is necessarily required. This is because of the fiber flow action which allows the individual fiber bundles to move into close proximity to one another and fill the spaces therebetween. Only a minimum amount of binder need be used to obtain exceedingly strong articles. The pressure applying apparatus may comprise a conventional stationary press of the type having cooperating flat platens. Alternatively, the pressure applying apparatus may comprise cooperating rotating belt or roller elements. Curved and shell-like articles can be formed depending on the mold shape. Fluid pressure molding techniques known in the plywood industry may be used as well. Any number of adhesive or binder substances and proportionate amounts thereof as necessary can be used to make board and similar articles from the rind strips.

The use of strips of rind in the manufacture of boards, panels and the like, has been explained wherein the long, continuous fiber bundles of the rind are retained as such in the resultant article. Instead of making structurally strong boards, for example, by pressing long strips of rind, the rind strips first may be cut up into relatively small chips about /1 inch to 1 /2 inches long, for example, These can be placed in bulk in a press or mold and subjected to heat and pressure so as to utilize the fiber flow phenomenon to bind and interlock the relatively short lengths of the fiber bundles into a structurally strong, composite, rigid article.

As an alternative to utilizing sugarcane rind in the manufacture of articles, the rind may be used as a source of raw material in the manufacture of paper. The fiber of sugarcane stalk is comparable to certain North American pulpwood in this regard. Furthermore, the fiber of sugarcane stalk is highly suitable for use in the manufacture of hardbo ard of the type wherein relatively short individual wood fibers are mixed with a binder and pressed, randomly disposed, into a dense sheetlike material under extremely high pressure.

In order to prepare the rind strips for such ultimate uses and to provide for the practical and efli-cient handling of the rind, the strips of rind can be processed into the form of dense, elongated, cylindrical pieces, for example, which are easy to store and transport. This is accomplished by subjecting the rind strips to a grinding or shredding action and thereafter to a compacting or compressing action which puts the fibers into the desired shape. The grinding action breaks up the fiber bundles into particulate form and the compressing action molds the particulate material into a highly compacted unit. The natural occurring cohesive characteristics of the rind fiber retain the particulate material in the molded shape.

In order to accomplish this, a continuous extrusion apparatus may be used wherein a screw conveyor rotating in sleeve member applies the grinding action to the rind to reduce it to particulate form and at the same time forces the particulate material into a confined area to appiy the compression action. This molds the rind into cylindrical pieces, the lengths of which can be made as desired. The extruding apparatus is explained by way of example. The grinding and compression operations can be performed by other mechanisms as well, and the particulate material may be pressed to shapes other than cylindrical units.

Whereas conventional processes for extracting the juice from sugarcane require the cutting, grinding and shredding of the rind of the stalk into bagasse, this process provides for the recovery of the juice without the destruction of the long fiber bundles of the rind and their ultimate utilization. Accordingly, instead of producing a mass of broken fibers intermingled with the pith of the stalk, ths process produces whole rind fiber bundles in the form of rind strips which strips are particularly suitable for a number of uses.

We claim:

1. A process for making articles such as board products from sugarcane fiber bundles comprising:

providing bundles of substantially uncrushed sugarcane rind fiber substantially free of sugarcane pith, relieving the natural bond between said individual sugarcane rind fiber bundles,

forming the sugarcane rind fiber bundles into the desired shape while the bond is relieved, and thereafter restoring the natural bond. 2. A process for making structural building products from sugarcane fiber bundles comprising:

providing bundles of substantially uncrushed sugarcane rind fiber substantially free of sugarcane pith, heating the sugarcane rind fiber bundles in a mold to relieve the natural bond between said sugarcane rind fiber bundles;

applying pressure to the sugarcane rind fiber bundles to form the fiber bundles into the shape of the mold; and

reducing the heat while maintaining pressure on the sugarcane rind fiber bundles.

3. A process for making articles from sugarcane fiber bundles comprising:

removing from the rind of sugarcane stalks substantialtially all material having only the rind composed of substantially uncrushed fiber bundles, substantially free of sugarcane pith;

loosening the fiber bundles mechanically with respect to one another;

forming the sugarcane fiber bundles into the desired shape by applying heat and pressure to the fiber bundles to relieve the natural bond between the sugarcane rind fiber bundles thereby allowing individual sugarcane rind fiber bundles to flow relative to one another under the influence of the pressure; and

thereafter removing the heat and pressure so as to restore the bond between the sugarcane rind fiber bundles.

4. A board product or the like comprising:

substantially uncrushed fiber bundles from sugarcane wherein the fiber bundles have been manipulated into a composite material of interlocked fiber bundles held together by the natural binder material of the sugarcane, said sugarcane rind fiber bundles being substantially free of sugarcane pith.

5. A board product, as defined in claim 4 including an additional binder material extending throughout.

6. A board product or the like comprising layers of sugarcane rind fiber bundles, substantially uncrushed and free of sugarcane pith, wherein the fiber bundles of each layer are aligned angularly and extend longitudinally in each layer in interlocked fashion and are held together by the natural binder material of the sugarcane.

References Cited UNITED STATES PATENTS 2,862,813 12/1958 Birdseye 162-96 XR 2,905,973 9/ 1959 Nolan 19-8 3,011,938 12/ 1961 Chapman. 3,303,089 2/ 1967 Roubicek et a1.

5 ROBERT F. BURNETT, Primary Examiner L. M. CARLIN, Assistant Examiner Lathrop et a1. 162-96 XR Roza 162-96- XR Irvine et a1. 161-150 Bobkowicz r 19-10 XR 10 16157, 170; 156-242, 296; 264258 Armstrong 19-9 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,464 ,8s Dated September Z 19 9 Inventor(s) Robert B M11161 11 8.1

It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

In The Claims Claim 3, line 4, change "having" to leaving Signed and sealed this 1st day of December 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents FORM PO-1050 (10-69,

USCOMM-DC 603764 09 u s GOVERNMINY "mum; OFFICE nu o-urssa 

